This invention relates to a light metal oxide-based amorphous solid. More particularly the present invention relates to an amorphous ternary composition consisting of alumina, boria, and an oxide of a light metal selected from Group IA and IIA of the Periodic Table of Elements, forming an electrically conductive solid. The conductor is useful as an element of a moisture and/or high temperature sensor.
Electrically conductive metallic glasses are well known. Conductivity, also, can be imparted to a glassy material by coating the solid material with a conductor, or by incorporation of a conductor into the glassy material. Homogeneous oxide glasses without transition metal dopants, typically, are not conductors. In certain compositions, however, incorporation of multivalent transition metal ions into the structure can form a useful semiconductor.
It is therefore an object of the present invention to provide a light metal oxide-based composition which forms an amorphous solid having electrical conductivity.